World Ocean Heat Content 0-700 m - 1955-2010

Time series of seasonal (red dots) and annual average (black line) of global upper ocean heat content for the 0-700m layer since 1955. More information: BAMS State of the Climate in 2009.
While ocean heat content varies significantly from place to place and from year-to-year (as a result of changing ocean currents and natural variability), there is a strong trend during the period of reliable measurements. Increasing heat content in the ocean is also consistent with sea level rise, which is occurring mostly as a result of thermal expansion of the ocean water as it warms.
Source: NOAA
(The text for the image(s) on this Web page was taken from the above source.)